As Biden's views were publishsed, fighting raged Saturday in Gaza, six weeks after a shock Hamas attack sparked an air and ground offensive by Israel, which has vowed to destroy the Palestinian militant group.
About 1,200 people, mostly civilians, were killed in Israel during the October 7 attack and around 240 taken hostage, according to Israeli officials.
In Gaza, around 12,300 people, more than 5,000 of them children, have been killed in the conflict, officials in the Hamas-run territory have said.
Here are five key developments from the past 24 hours:
"As we strive for peace, Gaza and the West Bank should be reunited under a single governance structure, ultimately under a revitalized Palestinian Authority, as we all work toward a two-state solution," Biden wrote in the piece published in The Washington Post.
Israel's top ally Washington has given its full backing to the country's response to the October 7 shock attack by Hamas, which left 1,200 dead, mostly civilians. About 240 people were taken hostage.
But as the death toll from Israel's military campaign in Gaza continues to climb -- to 12,300 people, including more than 5,000 children, according to the Hamas government -- the United States has voiced concerns over the manner of the strikes, and raised questions over the long-term future of the territory once Hamas is vanquished.
"A two-state solution is the only way to ensure the long-term security of both the Israeli and Palestinian people. Though right now it may seem like that future has never been further away, this crisis has made it more imperative than ever," Biden said.
Israeli Prime Minister Benjamin Netanyahu did not reject Biden's plan, but said the Palestinian Authority "in its current form is not capable of receiving responsibility for Gaza."
Palestinian president Mahmud Abbas has not condemned the Hamas attack and his senior ministers are celebrating it, Netanyahu said.
"We can't have a civilian authority in Gaza that supports terror, encourages terror, pays terror, and teaches terror," he said at a news conference.
Abbas, meanwhile, appealed to Biden to use his "significant influence" on Israel "to intervene immediately to... stop this humanitarian catastrophe, this genocide against our innocent people."
In his letter, Biden also threatened sanctions against settlers committing violence against Palestinians in the West Bank amid the conflict in Gaza.
"I have been emphatic with Israel's leaders that extremist violence against Palestinians in the West Bank must stop and that those committing the violence must be held accountable," he said.
"The United States is prepared to take our own steps, including issuing visa bans against extremists attacking civilians in the West Bank."
Refugee camp hit twice
A health ministry official in the Hamas-run Gaza Strip said more than 80 people were killed in two separate Israeli strikes on the Jabalia refugee camp.
"At least 50 people" were killed in an Israeli strike on the UN-run Al-Fakhura school, which had been converted into a shelter for displaced Palestinians, the official told AFP.
A separate strike on another building killed 32 people from the same family, 19 of them children, the official added.
The Israeli army did not specifically comment on the strikes but said its troops were expanding operations in Gaza, including in parts of Jabalia, to "target terrorists and strike Hamas infrastructure."
Hundreds flee hospital
Hundreds of people left Gaza's Al-Shifa hospital on foot, an AFP journalist at the scene saw, after the hospital director said the Israeli army ordered the facility's evacuation.
Hamas health officials said 120 wounded were still at the facility, along with an unspecified number of premature babies.
Israel's army denied ordering the evacuation, saying it "acceded" to a request from hospital directors to allow people to leave.
Al-Shifa hospital -- Gaza's biggest -- has become a focal point of the war. Israel alleges Hamas operates a base underneath the complex, a charge the Islamists deny.
Fuel enters Gaza under Israel-US deal
The first deliveries of fuel entered Gaza from Egypt after Israel agreed to a US request to allow limited deliveries to end a communications blackout that has halted aid convoys for two days.
The UN agency for Palestinian refugees, UNRWA, said Israel agreed to allow in 60,000 litres (16,000 gallons) of fuel a day from Egypt, but warned it was little more than a third of what is needed to keep hospitals, water and sanitation facilities running.
West Bank militants killed
Five fighters in the armed wing of Palestinian president Mahmud Abbas's Fatah party were killed overnight in a rare Israeli air strike on the occupied West Bank, the Palestinian Red Crescent and Fatah sources said.
The Israeli army said it had killed "a number of terrorists" in a strike on the Balata refugee camp in Nablus.
Israel march for hostages
Thousands of Israelis including friends and relatives of hostages taken by Hamas arrived in Jerusalem, capping a four-day march to pressure the government to secure the captives' release.
Since Hamas militants surged out of Gaza six weeks ago and, according to Israel, seized some 240 hostages, their loved ones have waged a determined campaign for their freedom.
A column of thousands of demonstrators draped in white and blue Israeli flags reached Prime Minister Benjamin Netanyahu's office chanting: "Bring them home now."
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